title: [Membrane potential of Pseudomonas aeruginosa spheroplasts having a cyanide-resistant respiration].
abstract: The membrane potential (delta psi) of Ps. aeruginosa spheroplasts was measured by a hydrophobic cation--tetraphenylphosphonium (TPP+) under conditions of simultaneous and separate action of the main respiratory chain and cyanide-resistant oxidase. In all cases, oxidation of endogenous substrates by spheroplasts was followed by generation of a membrane potential of the value of 127--156 mv. An addition of 1 mM cyanide did not practically affect the potential value. The discharge of the potential was attained by further addition of dicyclohexylcarbodiimide (DCCD) or valinomycin. The oxidation of the substrates added by the main respiratory chain was accompanied by an additional increase in the potential by 20--30 mv. In this case, an addition of cyanide decreased the potential by the same value. Oxidation of all substrates, except for TMPD+ ascorbate under conditions of functioning of cyanide-resistant oxidase also increased the potential by 15--50 mv. However, in this case cyanide did not practically affect the increase of the potential. The gain in the potential under TMPD + ascorbate oxidation by cyanide-resistant spheroplasts is prevented by cyanide. A question is discussed as to whether the transfer of reducing equivalents directly via cyanide-resistant oxidase is associated with the generation of a membrane potential or its functioning is not connected with the accumulation of energy in the form available for the cell.
mesh_terms: D003486:Cyanides / Q000494:pharmacology*; D004024:Dicyclohexylcarbodiimide / Q000494:pharmacology; D004352:Drug Resistance, Microbial; D007700:Kinetics; D008564:Membrane Potentials / Q000187:drug effects; D010101:Oxygen Consumption / Q000187:drug effects*; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000502:physiology*; D013104:Spheroplasts / Q000502:physiology; D014634:Valinomycin / Q000494:pharmacology
chemical_list: D003486:Cyanides; D014634:Valinomycin; D004024:Dicyclohexylcarbodiimide
vernacular_title: Membrannyĭ potentsial sferoplastov Pseudomonas aeruginosa, obladaiushchikh tsianidresistentnym dykhaniem.